Table 1288
Bitfields for segment attributes:
Bit(s)  Description     
 0      data segment rather than code segment
 1      unused???
 2      real mode
 3      iterated
 4      movable
 5      sharable
 6      preloaded rather than demand-loaded
 7      execute-only (code) or read-only (data)
 8      relocations (directly following code for this segment)
 9      debug info present
 10,11  80286 DPL bits
 12     discardable
 13-15  discard priority